What you attain after you fail to impress a woman you're attracted to. Usually initiated by the woman saying, "You're such a good friend". Usually associated with long days of suffering and watching your love interest hop from one bad relationship to another. Verb tense is "Friend-ed".

"I spent all that money on a date, just to find out she put me in the Friend Zone(said with eerie echo)."

Definition:
A state of being where a male inadvertently becomes a 'platonic friend' of an attractive female who he was trying to intitate a romantic relationship. Females have been rumored to arrive in the Friend Zone, but reports are unsubstanciated.

Girl:
"I love you (Insert the poor bastard's name here,) but I dont want to ruin a great friendship by dating you."
Guy:
"Well why the fuck did I waste two months on you?"

Men don't have platonic friends. We just have women we haven't fucked -yet-..."as soon as I figure this out, I'm in there!".

I mean, we got some platonic friends, we go "Oh no I got some but they all by accident - every platonic friend i got is some women I was trying to fuck, i made a wrong turn somewhere, and ended up in the friend zone - Oh No! I'm in the Friend Zone!".

"you're really great, you're just such a good friend" and a million derivatives there of. Most likely being said around the globe as you read this.

“The ‘friend zone’ is like the penalty box of dating, only you can never get out. Once a girl decides you’re her ‘friend,’ it’s game over. You’ve become a complete non-sexual entity in her eyes, like her brother, or a lamp.” - Ryan Reynolds in Just Friends

A myth based on a lie straight women tell their ugly straight male friends as a less hurtful way of rejecting their sexual advances. It is said that if a man doesn't immediately make his romantic intentions known that the woman will forever consider him a friend. He is then said to be in the "friend zone."

Julie: "Fred's a nice guy, but he's kinda fat and ugly, so when he asked me out, I told him I didn't want to risk ruining our friendship. I mean, maybe if he lost a few pounds..."
Nancy: "Good idea. That way his feelings aren't hurt. You really sidestepped that one."

Fred: "Julie's totally into me, but she considers the friendship too important to act on her intense desire for me."
Steve: "Aw, man, you're totally in the friend zone. That sucks. So what now?"
Fred: "Well, I guess I have to keep trying, right? I mean, she must find me attractive."
Steve: "Totally."